1. New plugs. I believe it was to a colder plug. What does that do for
carbonization of the back sides of the valves? Checked www.boschusa.com and
they don't list a plug for the 2000 4.7l, maybe that's the reason people are
telling you not to put them in? On the other hand, NGK makes a direct cross
in a platinum. Maybe that's the way to go?
Answer: The Bosch plugs for your vehicle are 4418 for platinum+4's and 4230
for platinum's. A lot of DML'ers choose one step colder plug which would
make them 4417 and 4229 respectively. This, again, is for pinging. Cooler
plugs dissipate more heat from the cylinder area thereby lessening possible
detonation problems.
2. Timing. What I've gathered from this and other forums is that the 4.7l
can take more advance than the other models but the timing gets retarded
because of a generic flash update that is common to all 2000 (01?) Dakotas.
The other motors are having more troubles with this than the 4.7l? So if I
can find a chip that advances the timing I'll get better economy but lose a
little bottom end grunt?
Answer: I think it's the other way around. If you advance the timing you'll
need higher octane fuel. The higher the octane the harder it is to ignite.
You need this to prevent detonation. When you advance timing your spark
gets there sooner. I can see you're trying to get the best of both worlds
here which is really going to be difficult because of the type of vehicle
you have chosen to purchase.
3. Cat back exhaust. So far the only product to make a specific claim of
better mileage in thier ads. My concern is it also says 'more power'. In
general you need X gallons of fuel to make X Hp. So if you make more power
one would think you'd burn more gas. In most computer controlled motors
they adjust the air/fuel mixture so if you alter one side of the equastion
by adding more air, won't the computer just compinsate by adding more fuel?
The only other explanation is that the exhaust improves on the efficiency
(sp?) of the motor. Are these systems louder/noisier than stock?
Answer: Efficiencies of the engine could give you mileage gains but if you
think this one mod will make that big of difference think again. If you
free up flow at one end, you need to free up flow at the other. There's no
point exhaling when you haven't inhaled. Most of these systems are quite a
bit louder than stock.
4. Synthetic fluids. I've seen a number of posts regarding this and I
think that going to Mobil 1 is gonna be a given. Ran it in my old vehicle
and loved it. I've seen posts saying not to run synthetic transmission
fluid for one reason or another, something about the different types of
synthetic. You gotta make sure you get the right one or you can cause more
damage then save. How about differential fluid? It seems to me that the
diff fluid in my truck has the consistency of roofing tar. Sometimes I can
drive 5 or 6 miles before it locks up and the RPMs drop to normal,
especially true in cold weather.
I can't speak enough of synthetic fluids. They are a lot more slippery than
dino oil. No varnish build up. You can run the engine oil for 10K-20K
miles with no change provided you change the filter at the normal intervals
(3K-5K miles) and you use a good filter (NO Fram!). Automatic transmissions
must have ATF+3 Type 7176 fluid. Synthetics that have these specifications
are Amsoil and Redline. Differential fluids are 75W90. I believe a lot of
DML'ers use Amsoil. Most people use Mobil 1 for the engine. It seems to be
the easiest to find. I use Castrol Syntec which I buy from Costco at a
fairly good price. I haven't had any problems with it, though I believe
there was some controversy way back when there was some dispute between
Mobil and Castrol.
5. Thermostat. A number of people have suggested this. I'm really not
sure what this will do for me. I guess it's feasable that a cooler running
motor means cooler cylinders and less likelyhood of ping. But I'm not
having that problem. If I manage to get the timing advanced maybe I will?
Comments are welcome on this one.
Answer: This is another "running the engine cooler" mod. You'll not realize
any power gains. Will it help economy? Maybe a tad bit. Theory is your
engine runs best at 183º coolant temperature. Therefore a change to a 180º
t-stat is the best. For those that ping this is a definite change for the
better. For your 4.7 engine changing it is a pain. I have a 5.9 and my
timing's advanced. I run 92+ octane fuel but my t-stat is still a 195.
6. Snake oil. Read a few posts about fuel line magnets and fuel catalysts
but I really wonder what the deal is. I found a report on the EPA page
about some of the products that were tested and proven to improve mileage
but haven't been able to read the results from the individual test to see
which one made the biggest change.
Answer: You said it right! "Snake oil". Fuel catalysts? You mean stuff
that can increase the octane? Some of those will but it's going to be
expensive adding that every time you gas up.
HTH,
Ron
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